import i3bar_base
import strutils
import std/times
import std/os

proc battery_exists(): bool =
  let state = strip(readFile("/sys/class/power_supply/BAT0/present"))
  if state == "1":
    return true
  return false

proc is_charging(): bool =
  let state = strip(readFile("/sys/class/power_supply/BAT0/status"))
  case state:
    of "Charging":
      return true
    else:
      return false

proc get_charge(): int =
  var charge = 0
  let chg = strip(readFile("/sys/class/power_supply/BAT0/capacity"))
  if chg != "":
    charge = parseInt(chg)
  return charge

proc get_design(charge: int, state: bool): (string, string, string, string) =
  var icon = " "
  var icon_colour = lightgreen
  var col = foreground
  var bg = black
  var border = lightgreen
  if is_charging():
    icon = " "
  else:
    case charge:
      of 0..5:
        icon_colour = black
        col = black
        bg = red
      of 6..19:
        icon_colour = alert
        border = alert
      of 20..39:
        icon_colour = yellow
        border = yellow
        icon = " "
      of 40..59:
        icon_colour = green
        border= green
        icon = " "
      of 60..79:
        icon_colour = green
        border= green
        icon = " "
      of 80..100:
        icon_colour = lightgreen
        border = lightgreen
        icon = " "
      else:
        icon = "x "

  let text = "<span foreground=\"" & icon_colour & "\">" & icon & "</span>" & $charge & "%" 
  return (text, col, bg, border)

proc get_output(charge: int, state: bool): i3barData =
  let (text,col,bg_col,bord_col) = get_design(charge, state)
  let data = i3barData(
    full_text: text,
    color: col,
    border: bord_col,
    background: bg_col
    )
  return data


proc get_battery_info() =
  var last_charge = -1
  var last_state = false
  while true:
    let charge = get_charge()
    let state = is_charging()
    if charge != last_charge or state != last_state:
      let data = get_output(charge, state)
      outputJSON(data)
      last_charge = charge
      last_state = state
    sleep(1000)

proc main() =
  if battery_exists():
    get_battery_info()

main()